Woven fabric excellent in transparency, and down jacket

ABSTRACT

An object of the present invention is to provide a woven fabric having high transparency that a batting is made see-through, having a strength necessary for side clothes of clothing or futons, and further having a low air-permeability in order to provide an unprecedented clothing or futon whose batting is seen through. A woven fabric of the present invention is characterized in comprising a multifilament having a single yarn fineness of 0.5 to 3.0 dtex and a total fineness of 3 to 25 dtex, wherein the woven fabric has a cover factor of 1300 to 2500, a visible light transmittance of 25% to 80%, and an L* value of 37 or higher.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a woven fabric having transparency, particularly to a woven fabric used suitably for a side cloth of a down wear, a down jacket, a futon (Japanese-style mattress), a sleeping bag or others.

(2) Description of Related Art

A woven fabric used for a side cloth of a down wear or a feather futon is required to be high in woven fabric strength and low in air-permeability in order to restrain cotton or down from spouting out, while the woven fabric is prevented from being torn. Recently, the woven fabric is required not only to be merely low in air-permeability but also to be lighter, soft in feeling, and high in design and fashionability.

However, in order to make a woven fabric light, it is indispensable to make the woven fabric thin or reduce the fineness of a multifilament constituting the woven fabric. Thus, it is difficult to maintain the strength of the woven fabric.

As an example coping with such problems, known is, for example, a woven fabric composed of a base yarn made of a synthetic fiber and a reinforcing yarn in which the base yarn has a fineness of 10 to 30 dtex and the reinforcing yarn has a fineness of 20 to 60 dtex (Patent document 1). In this woven fabric, the reinforcing yarn is integrated at regular intervals into the arrangement of the warp and/or that of the weft, thereby preventing the woven fabric from being declined in tear strength.

As another example, known is a thin woven fabric or the like that is made of a synthetic fiber multifilament having a fineness of 15 to 40 dtex and is subjected to resin finishes with a silicone resin to gain a sufficient tear strength (Patent document 2).

As a woven fabric usable suitably for, in particular, a side cloth of a down jacket, for example, a woven fabric is provided which is produced by weaving using a polyamide multifilament having a yarn fineness of 30 dtex or less, a single yarn fineness of 1.2 dtex or less and an intended tear strength (Patent document 3).

-   Patent document 1: JP-A-2004-316015 -   Patent document 2: JP-A-2008-101295 -   Patent document 3: JP-A-2005-48298

In the meantime, down, cotton, feather or the like used in a down jacket and others are not usually subjected to a process for making the design thereof high. Thus, they are not attractive. For the reason, the changes of a sewing-design, color or pattern of a side cloth contributed to the improvement of the fashionability of the conventional down jackets, in order that their batting such as down cannot be seen as much as possible.

The present inventors have hit upon an idea that contrarily to the conventional one, the design of clothing is heightened by making the transparency of its side cloth high to let its batting see positively. Thus, the inventors have investigated the techniques mentioned above to provide a woven fabric having transparency.

However, the woven fabric of Patent document 1 is lacking in aesthetic merit since its reinforcing yarn looks longitudinal stripes or weft spots. Thus, the woven fabric is not a woven fabric that can sufficiently express the beauty of a batting. About the woven fabrics of Patent document 2 and Patent document 3, it is not said that the fineness thereof is sufficiently small. Thus, the woven fabrics do not have desired transparency.

SUMMARY OF THE INVENTION

Under such a situation, an object of the present invention is to provide a woven fabric having such high transparency that a batting is made see-through, having a strength necessary for side clothes of clothing or futons, and further having a low air-permeability in order to provide an unprecedented clothing or futon whose batting is seen through.

In order to solve the above-mentioned problems, as a result of an earnest study, the inventors have found the following matters and achieved the invention; a woven fabric having very high transparency in the visible light transmittance of 25 to 80% while maintaining a strength and a low air-permeability necessary for the woven fabric may be provided, by using a multifilament having a single yarn fineness of 0.5 to 3.0 dtex and a total fineness of 3 to 25 dtex, controlling a cover factor of the woven fabric being 1300 to 2500, and further controlling L* value brightness of the woven fabric being 37 or higher after the woven fabric is subjected to dyeing.

A woven fabric of the present invention is characterized in comprising a multifilament having a single yarn fineness of 0.5 to 3.0 dtex and a total fineness of 3 to 25 dtex, wherein the woven fabric has a cover factor of 1300 to 2500, a visible light transmittance of 25% to 80%, and an L* value of 37 or higher.

In the preferable embodiment, the multifilament has a refractive index of 1.47 to 1.57 in a fiber cross-sectional direction.

In other preferable embodiment, the multifilament contains titanium oxide in an amount of 0% to 0.5% by mass, and has a breaking strength of 3.5 to 10 cN/dtex.

In other preferable embodiment, at least one surface of the woven fabric is subjected to calendering, and the woven fabric has a fluorine resin coating on a surface thereof.

Additionally, the present application includes a down jacket comprising a woven fabric as set for in claim 1 as a side cloth and a colored batting.

The present invention provides a woven fabric high in transparency and excellent in aesthetic merit. This woven fabric has intended tear strength and is thin and light. Furthermore, this woven fabric is favorably usable for a side cloth of a down wear, a down jacket, a futon, a sleeping bag or some other since the woven fabric is low in air-permeability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional photograph of the woven fabric produced in Example 1 (after calendering).

FIG. 2 is a weaving pattern that illustrates an example of the woven fabric of the present invention.

FIG. 3. is a weaving pattern that illustrates other example of the woven fabric of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 1. Multifilament

The woven fabric of the present invention is produced by weaving a multifilament. First, we will explain the multifilament specifically.

The multifilament for the present invention is formed by twisting filaments (hereinafter referred to as “monofilaments” also) together. In order to provide the resultant woven fabric having a certain level of strength and exhibit transparency simultaneously, the multifilament may have a fineness (total fineness) of, for example, 3 dtex or more, preferably 5 dtex or more, more preferably 7 dtex or more. The multifilament may have a fineness of 25 dtex or less, preferably 16 dtex or less, more preferably 12 dtex or less. When the fineness of the multifilament is set into the range, a woven fabric may be provided which has high transparency and intended strength and is light and thin. However, when the fineness of the multifilament is less than 3 dtex, it is difficult that the resultant woven fabric exhibits a sufficient strength. When the fineness is more than 25 dtex, the woven fabric may be low in transparency.

The breaking strength of the multifilament is preferably higher. The multifilament may have a breaking strength of, for example, 3.5 cN/dtex or higher, more preferably 4.0 cN/dtex or higher, even more preferably 4.5 cN/dtex or higher, preferably 10 cN/dtex or lower, more preferably 6 cN/dtex or lower, even more preferably 5.5 cN/dtex or lower. When the strength of the multifilament is 3.5 cN/dtex or higher, in the case of using the multifilament having a high degree of flatness, the resultant woven fabric exhibits an appropriate tear strength.

The breaking elongation of the multifilament is not particularly limited. The multifilament may have a breaking elongation of preferably 35% or more, more preferably 38% or more, preferably 50% or less, more preferably 48% or less. When the breaking elongation is less than 35%, the woven fabric is easily torn, since the stress concentrates to one monofilament when the force is applied to the woven fabric. On the other hand, when the breaking elongation is more than 50%, the yarn is extended fully by strong tension which arises from a friction on a various yarn-fixing-parts (i.e., for example, an apparatus or the like in order to allow the weaving to speed up or to increase a density of the woven fabric), thereby the yarn gets easy to break. Moreover, since the breaking strength becomes low, a problem that the tear strength of the woven fabric decreases will arise.

The number of the monofilaments constituting one multifilament, is arbitrarily set depending on a relation between the fineness (total fineness) of multifilament and the fineness of monofilament, preferably, for example, 2 or more, more preferably 3 or more, even more preferably 5 or more, preferably 35 or less, more preferably 25 or less, even more preferably 15 or less. When the number of the filament is set into the range, the stress applying to the woven fabric is dispersed into many monofilaments without concentrating to one monofilament. As a result, the stress applied to each yarn is decreased so that the tear strength of the woven fabric appears to be improved.

In the present invention, it is preferred not to use titanium oxide as an agent for dullness if possible. However, in order to improve the spinnability, titanium oxide may be properly added thereto to form the filament. Titanium oxide is contained in the resin constituting the multifilament in a proportion of preferably 0% to 0.5%, more preferably 0% to 0.1%, even more preferably 0% to 0.05%, most preferably 0% by mass of the whole of the resin (100% by mass). When the proportion of contained titanium oxide is set into the range, the transparency of the woven fabric can be favorably exhibited.

In order to improve the transparency of the woven fabric, it is important to restrain light from being absorbed inside of the yarn, being refracted and reflecting diffusely. For the reason, the refractive index (in a fiber cross-sectional direction) of the multifilament in the present invention is preferably closer to the refractive index of air to restrain light from reflecting and being refracted on the surface of the woven fabric. The refractive index (in the fiber cross-sectional direction) of the multifilament is, for example, preferably 1.47 or higher, more preferably 1.48 or higher, even more preferably 1.49 or higher, and preferably 1.57 or lower, more preferably 1.55 or lower, even more preferably 1.52 or lower. When the refractive index of the resin is set into this range, the reflection or refraction of light is suppressed so that it may be possible to produce a woven fabric better in transparency. A method for measuring the refractive index of the multifilament will be described in detail in item “Examples”.

The following describes the monofilaments constituting the multifilament specifically.

The fineness of the monofilament (single yarn fineness) is 0.5 dtex or more, preferably 1.0 dtex or more, more preferably 1.2 dtex or more, 3.0 dtex or less, preferably 2.5 dtex or less. When the fineness of the monofilament is set into the range, the woven fabric is provided that has appropriate tear strength and low air permeability. On the other hand, when the fineness of the monofilament is less than 0.5 dtex, it may cause that the transparency of the woven fabric is reduced or appropriate tear strength cannot be achieved. Additionally, when the fineness of the monofilament is more than 3.0 dtex, the air permeability might be worsened and the woven fabric might not gain a soft feeling.

The intrinsic viscosity of the resin which is a material of the monofilament, in case of using polyesters, is preferably 0.58 or more, more preferably 0.60 or more, preferably 1.00 or less, more preferably 0.90 or less. When the intrinsic viscosity of the resin is set into the range, it is possible to produce monofilament having appropriate breaking strength and reduce the manufacturing cost. Additionally, the example where the intrinsic viscosity of the resin is 0.58 or more is preferable, since it is possible to produce a monofilament having uniform cross-section stably in case of producing monofilaments having a cross-section in a form of flat. On the other hand, when intrinsic viscosity of the resin is less than 0.58, some problems will arise in case of producing monofilaments having a cross-section in a form of flat. Here, the above-mentioned “problems” are that the tear strength or the breaking strength of the product decreases, that the processing operatability is deteriorated for lacking of the breaking elongation, that the durability of the product is deteriorated and the like. This is because that the breaking strength of the monofilament having a flat cross-section is smaller than that of the monofilament having a circle cross-section. In contrast, the example where intrinsic viscosity is more than 1.00 is not preferable for lacking of the practicality due to the high production cost in producing a woven fabric.

For example, in the case of nylon, the relative viscosity of polymer which is the material for the monofilament is preferably 2.0 or more, more preferably 3.0 or more, preferably 4.5 or less, more preferably 3.5 or less. When the resin has a relative viscosity of 2.0 or more, the resultant fiber has an appropriate breaking strength. In addition, when the resin has a relative viscosity of 3.0 or more, that makes it possible to produce a monofilament having cross-section with high flat ratio stably. On the other hand, when the resin has a relative viscosity of less than 2.0, problems will arise in case of producing monofilaments having a cross-section in a form of flat. Here, the above-mentioned “problems” are that the tear strength or the breaking strength of the product decreases, that the processing operatability is deteriorated for lacking of the breaking elongation, that the durability of the product is deteriorated and the like. This is because that the breaking strength of the monofilament having a flat cross-section is smaller than that of the monofilament having a circle cross-section. Moreover, the example where the resin has a relative viscosity of more than 4.5 is not preferable due to the high production cost for the deterioration of yarn-making operatability.

The material resin of the monofilament is not particularly limited. The material resin may include polyesters such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate and the like; polyolefins such as polyethylene, polypropylene and the like; polyamides such as nylon 6, nylon 66, nylon 46, nylon 12, nylon 610, nylon 612, copolymers thereof and the like; other various polymers such as acrylonitrile, polyvinyl chloride, polyvinyl alcohol, polystyrene, cellulose and the like. Among them, polyamides are preferable for providing a soft feeling while using the monofilament having a modified cross-section.

The general fiber having a refractive index as mentioned above may include a polyolefin fiber such as a polyethylene fiber, a polypropylene fiber and the like; a polystyrene fiber; a polyester fiber such as a polyethylene terephthalate fiber; a polyamide fiber such as a nylon 6 fiber, a nylon 66 fiber and the like; an acrylic fiber; a cellulose fiber such as a tri-(di) acetate fiber, cupra, rayon and the like. Among them, the preferred fibers are a polyester fiber or a polyamide fiber. In particular, a nylon 6 fiber and a nylon 66 fiber are more preferable for the present invention for achieving both fiber strength and transparency at the same time.

If necessary, the following may be added, alone or in the form of a mixture, to the monofilaments: a hygroscopic material, an antioxidant, a delustering agent, an ultraviolet absorbent, an antibacterial agent, and others. It is however necessary to pay attention to the kind and the concentration of the additives when adding in order not to deteriorate the filament in transparency. It is also preferred to make the elongation of the monofilaments high to improve the breaking elongation of the woven fabric.

The multifilament, such as polyamide based multifilaments or polyester based multifilaments, can be produced by use of a spin-draw continuous machine in a spin-draw mode, or through two steps using a spinning machine and a drawing machine. In the spin-draw mode, the rotary speed of the spin yarn pulling godet roller is set into the range preferably from 1500 to 4000 m/minute.

2. Woven Fabric

The woven fabric of the present invention is a woven fabric containing the multifilament in a proportion of 50% or higher. The woven fabric is more preferable as the blend proportion of the multifilament is larger.

The weaving pattern of the woven fabric is not particularly limited. The weaving pattern may include any weave such as plain weave, twill weave or satin weave. The weaving pattern is preferably plain weave since this weave can restrain the air-permeability. In order to raise the tear strength of the woven fabric, ripstop taffeta, particularly, double-ripstop is preferably employed. The weave is preferably, for example, a weave illustrated in FIG. 2 or 3.

A weaving machine used to produce the woven fabric is not particularly limited, and may be appropriately selected from a water jet loom, an air jet loom, a rapier loom, and others.

The woven fabric may have a warp density of preferably 140 to 380 threads/inch, more preferably 200 to 250 threads/inch. The woven fabric may have a weft density of preferably 100 to 350 threads/inch, more preferably 140 to 250 threads/inch. The gray woven fabric density of the woven fabric may be equal to or different from the finish density thereof.

The woven fabric may have a cover (CF) of 1300 to 2500, preferably 1450 or more, more preferably, even more preferably 1550 or more, preferably 2000 or less, more preferably 1700 or less. When the cover factor is set into the range, a woven fabric is provided which is thin and light, and has a low air permeability. When the cover factor of the woven fabric is less than 1300, it might bring a difficulty to provide the woven fabric with appropriate air permeability. On the other hand, when the cover factor is more than 2500, it might bring a difficulty to provide the woven fabric being light and having a high transparency, while the woven fabric which is low in air permeability may be provided.

Here, the cover factor of the woven fabric (CF) is defined by the following equation.

CF=T×(DT)^(1/2) +W×(DW)^(1/2)

, wherein T and W indicate the warp density and the weft density (the number of threads/inch) of the woven fabric, and DT and DW indicate the fineness (dtex) of the warp constituting the woven fabric and that (dtex) of the weft constituting it.

The woven fabric may have a weight per unit area that ranges from preferably 10 g/m² or more, more preferably 15 g/m² or more, preferably 60 g/m² or less, more preferably 45 g/m² or less, even more preferably 30 g/m² or less. The example where the weight per unit area of the woven fabric is set into the range is preferable, in order to provide the woven fabric being thin and light, and low in air permeability. On the other hand, the example where the weight per unit area of the woven fabric is less than 10 g/m² is not preferable, since it might bring a difficulty to provide a woven fabric which is low in air permeability. Additionally, the example where the weight per unit area of the woven fabric is more than 60 g/m² is not preferable, since that makes a thickness of the woven fabric thick while keeping the air permeability low.

3. Various Finishes

Hereinafter, a description will be made about various methods for finishes the woven fabric.

In the present invention, the woven fabric after produced by weaving may be dyed. A color may be arbitrarily selected depending on end-use of the woven fabric. When the color is dark, it is concerned that it makes difficult that a batting inside the woven fabric can be seen from the outside since the woven fabric is lowered in visible light transmittance. Thus, in order to make good use of, particularly, the transparency of the woven fabric, it is preferred to dye the woven fabric into a color high in brightness, such as a white, beige, gray, or pink. The method for dyeing the woven fabric may illustrate a method comprising steps letting the woven fabric after weaving subjected to refining, relaxing, pre-setting, dyeing and finishing techniques, with use of a processing machine and the like.

In the present invention, at least one surface of the woven fabric is preferably subjected to calendering. When at least one surface of the woven fabric has been subjected to calendering, the monofilaments are aligned in the calendered surface to be compressed and fixed. Thus, it is possible to produce a woven fabric low in air-permeability. When a flat filament is used, the calendering of the woven fabric makes the flat filament aligned in a direction parallel to any cross section of the woven fabric, and further makes the distance between flat filaments very short. Thus, the transparency of the woven fabric can be remarkably improved.

It is preferred that the woven fabric is subjected to calendering on only one surface thereof or on two surfaces thereof, particularly on only one surface thereof. Calendering contributes to improving the transparency of the woven fabric since the multifilament exposed on the surface of the woven fabric is compressed by calendering so that the woven fabric may have a smooth surface.

The calendered surface(s) may be used for an outside-air-side (outside) of a down jacket, and/or a cotton-side (inside) thereof. In order to restrain incident light from being reflected on the surface of the woven fabric, it is preferred to sew the woven fabric into a down jacket in such a manner that the calendered surface is rendered the cotton side (inside) of the down jacket. When both surfaces of the woven fabric are subjected to calendering, either one of the surfaces may be positioned to be on the cotton side (inside). When the number of times of the calendering is different between the surfaces, it is advisable to position the surface at which the number of times of calendering is larger towards the cotton side (inside).

The temperature for calendering is preferably 50° C. higher than the glass transition temperature of the material resin for the monofilament, more preferably 80° C. higher than the glass transition temperature. The temperature for calendering is preferably 20° C. lower than the melting point of the material resin for the monofilament, more preferably at least 30° C. lower than the melting point. When the calendering temperature is set into the range, a fabric is yielded which has both of a low air permeability and a high tear strength. On the other hand, if the calendering temperature is lower than “the glass transition temperature of the used material+50° C.”, the compression degree of the monofilaments in the multifilaments is weak so that a fabric low in air permeability is not easily yielded. If the temperature is higher than “the melting point of the used material−20° C.”, the compression degree of the monofilaments in the multifilaments is heightened; however, the tear strength of the fabric may be lowered. For example, when producing the monofilament from polyamide based resin, the calendering temperature is preferably from 130 to 200° C., more preferably from 120 to 190° C. When the material is a polyester, the calendering temperature is preferably from 140 to 240° C.

The pressure for the calendering is preferably is preferably 0.98 MPa (10 kgf/cm²) or more, more preferably 1.96 MPa (20 kgf/cm²) or more, preferably 5.88 MPa (60 kgf/cm²) or less, more preferably 4.90 MPa (50 kgf/cm²) or less. When the calendering pressure is set into the range, a fabric is yielded which has both of a low air permeability, and tear strength. On the other hand, when the calendering pressure is less than 0.98 MPa (10 kgf/cm²), the compression degree of the monofilaments in the multifilaments is small so that a fabric low in air permeability may not be yielded. When the calendering pressure is more than 5.88 MPa (60 kgf/cm²), the monofilaments in the multifilaments are excessively compressed so that the tear strength of the fabric may be lowered.

The raw material of the calender is not particularly limited. One of the two rolls thereof is preferably made of a metal. About the metal roll, the temperature of the roll itself can be adjusted, and further therethrough the cloth surface can be evenly compressed. The other roll is not particularly limited. The roll may be a resin roll or a metal roll. When using a resin roll, a nylon is a preferable material of the surface thereof.

For your reference, the number of calendering is not particularly limited, therefore the number thereof may encompass only one or more than one.

In the present invention, a surface of the woven fabric after weaving, may be subjected to water repellent treatment. A water repellent therefor may be an ordinary water repellent for fibers. A preferred water repellent may be, for example, a silicone water repellent, a fluorine water repellent made of a perfluoroalkyl-group-containing polymer, or a paraffin water repellent. Among them, the use of the fluorine water repellent (in particular, any perfluoroalkyl acrylate polymer) is particularly preferred, since the refractive index of the coat can be controlled in a low level and further the reflection of light on the fiber surface can be decreased. The examples of the method for the water repellent treatment include a general method such as a padding method, a spraying method, a printing method, a coating method, or a gravure method.

Examples of the fluorine water repellent include fluorine deeply-dyeing agents and fluorine water/oil repellents.

Depending on your needs, the woven fabric may be subjected to various mechanical finishing techniques such as coating and laminating, or additionally to soft treatment or resin treatment for adjusting the feeling or strength of the woven fabric. The examples of a softener include amino-modified silicone, or a polyethylene, polyester or paraffin softener. The woven fabric may be subjected to a post-treatment for finish such as soft treatment, silicone treatment or the like. A variety of resin can be used as resin treatment agent, examples of the agents may include melamine resin, glyoxal resin, urethane resin, acrylic resin, polyester resin or the like.

4. Various Properties

The matter that the woven fabric of the present invention has desired transparency can be verified from a value of the visible light transmittance. In the present invention, the woven fabric may have a visible light transmittance of 25% or higher, preferably 30% or higher, more preferably 40% or higher, 80% or lower, preferably 70% or lower, more preferably 55% or lower. When the visible light transmittance is made higher than 80%, the transparency of the woven fabric is improved. However, in order to produce a woven fabric having such a high visible light transmittance, we found that it is required to reduce the density between the filaments. Such a woven fabric is not preferable since a batting therein may unfavorably spout out. On the other hand, when a visible light transmittance is lower than 25%, it is difficult for providing a woven fabric having a desired transparency.

The woven fabric of the invention is preferably in a color from white to a middle color range. For example, the woven fabric may have an L* value of 37 or higher, preferably 45 or higher, more preferably 70 or higher. On the other hand, the woven fabric may have an L* value of preferably 95 or lower, more preferably 90 or lower.

For reference, the L* value is standardized in Commission Internationale de l'Eclairage (CIE) in 1976. In Japan also, the value is employed in JIS Z 8729. The symbol (L*a*b*) is called the (CIE) 1976 (L*a*b*) color coordinate system. L* value indicates the brightness in this color coordinate system.

The woven fabric of the invention may have a visual inspection transparency of preferably class 3 or higher, more preferably class 3.5 or higher, even more preferably class 4 or higher. When the visual inspection transparency is set into this range, the transparency of the woven fabric is higher, so that a woven fabric which a batting can be more clearly seen through from the outside may be provided.

The woven fabric may have an air permeability, which is measured by Frazier type method, of preferably 1.5 cc/cm²/s or lower, more preferably 1.0 cc/cm²/s or lower. On the other hand, the lower limit of the air permeability may be preferably 0.01 cc/cm²/s or higher, more preferably 0.1 cc/cm²/s or higher. The example where the air permeability of the woven fabric is set into the range is preferable for being able to prevent a batting from spouting out.

The tear strength of the woven fabric, which is measured by pendulum method, is not in particular limited. In view of required performance of a side cloth for clothing and feather product, the woven fabric may have a tear strength in each of the warp and the weft direction that ranges from preferably 5 N or higher, more preferably 6 N or higher, even more preferably 7 N or higher. On the other hand, the woven fabric may have a tear strength of preferably 50 N or lower, more preferably 40 N or lower, even more preferably 25 N or lower. When the tear strength of the woven fabric is set into the range, it is possible to produce the woven fabric which is light and thin, and has required tear strength. When the tear strength is less than 5 N, there are some cases where the tear strength of the woven fabric is insufficient depending on the usage. On the other hand, the example where the tear strength is more than 50 N is not preferable, since it is required to increase the fineness, and in accordance with it, the woven fabric has a tendency to become thick and hard.

The woven fabric may have a thickness of, for example, preferably 0.001 to 0.1 mm, more preferably 0.005 to 0.06 mm. The embodiment where the woven fabric is thinner is preferable, since the woven fabric becomes more transparent.

The woven fabric of the present invention may be used as, for example, a side cloth of a down jacket or the like. Since the woven fabric of the invention is excellent in transparency, a batting can be seen through the woven fabric, unlike conventional down jackets. Thus, by using the woven fabric of the invention for a side cloth of a down jacket and filling a colored batting into the down jacket so as to dare to let the batting see, the down jacket can be provided as an unprecedented and highly aesthetic clothing. The used batting is not particularly limited, and is preferably, for example, down, feather (feather or small feather), cotton, or a fiber made of a synthetic resin such as polyester. These batting species may also be used in the form of a mixture. It is desired to use, as at least one part of the entire batting, a colored batting to heighten the aesthetic merit of clothing. A batting which is subjected to colored treatment may also be used.

EXAMPLES

The following will describe the present invention in detail by the reference of Examples; however, the present invention is not limited thereto. All examples produced by changing or modifying Examples are included in the technical scope of the present invention as far as the examples do not depart from the subject matters of the present invention that have been described above or will be described below. In the following, unless otherwise noted, “parts” means “parts by weight” and “%” means “% by weight.”

<Intrinsic Viscosity>

The intrinsic viscosity (IV) is a value defined by measuring the intrinsic viscosity[η] thereof at 30° C. using a mixed solvent composed of p-chlorophenol and tetrachloroethane (ratio of p-chlorophenol to tetrachloroethane=75/25), and converting the measured value into the intrinsic viscosity (IV) of a mixed solvent composed of phenol and tetrachloroethane (ratio of phenol to tetrachloroethane=60/40).

Intrinsic viscosity(IV)=0.8325×[η]+0.005

<Relative Viscosity>

A sample is dissolved in an extra pure reagent of concentrated sulfuric acid that has a concentration of 96.3±0.1% by mass to give a polymer concentration of 10 mg/mL. In this way, a sample solution is prepared. An Ostwald viscometer giving a water dropping time of 6 to 7 seconds at a temperature of 20±0.05° C. is used to measure the dropping time T₁ (seconds) of 20 mL of the prepared sample solution and the dropping time T₀ (seconds) of 20 mL of the concentrated sulfuric acid extra pure reagent, used for the dissolution of the sample, at 20±0.05° C. The relative viscosity (RV) of the used material is calculated from the following equation:

RV=T ₁ /T ₀

<Refractive Index>

A resin that is a raw material of a multifilament was used, and produced into a biaxially drawn film of 20 μm in thickness. This film was used and the refractive index thereof was analyzed in the film thickness direction in accordance with JIS K 7142-1996 5. 1 (method A), using an Abbe refractometer (4T type, manufactured by Atago Co., Ltd.) in which a light source is a sodium D line. This refractive index was used as the refractive index in the fiber cross-sectional direction of the multifilament. Conditions for the measurement were as follows: temperature: 23° C.; and relative humidity: 50%. In accordance with the kind of the resin, a contact liquid to be used was selected from examples in the JIS.

<Fineness (Total Fineness, Single Yarn Fineness)>

The total fineness of multifilaments (total fineness) is determined by preparing three cassettes of 100-m-long multifilaments therefrom, measuring the mass (g) of each of the cassettes, averaging the resultant masses, and then converting the average value to per 10000-m-long by multiplying the average value by 100.

The fineness of the monofilaments (single yarn fineness) is a value defined by dividing the fineness of the multifilaments by the number of the monofilaments.

<Breaking Strength, Breaking Elongation>

A 4301-model of a universal material testing machine manufactured by Instron Japan Co., Ltd. is used to apply, to a sample (sample length: 20 cm, and tensile speed: 20 cm/minute), a load of 1/33 gram per fineness (denier), thereby, a S—S chart is created. This measurement is made three times. Breaking strength and breaking elongation are measured from the chart respectively, and the average thereof is defined as the breaking strength and breaking elongation.

<Cover Factor>

The cover factor of the woven fabric (CF) is defined by the following equation.

CF=T×(DT)^(1/2) +W×( DW)^(1/2)

, wherein T and W indicate the warp density and the weft density (the number of threads/inch) of the woven fabric, and DT and DW indicate the fineness (dtex) of the warp constituting the woven fabric and that (dtex) of the weft constituting it.

<Weight Per Unit Area>

The weight of a fabric per unit area is measured with reference to the mass per unit area prescribed in JIS L 1096 8.4.

Here, in examples 1-5, 7, comparative examples 1-2, we measured the weight per unit area of the woven fabric which was processed by water repellent treatment. In examples 6 and 8, we measured the weight per unit area of the woven fabric which was produced without processing water repellent treatment.

<Visible Light Transmittance>

A spectrophotometer (UV-3100PC manufactured by Shimadzu Corp.) was used to measure the visible light transmittance of any sample in a wavelength range of 380 to 780 nm. An integrating sphere attached to this photometer was an ISR-3100 integrating sphere having an inside diameter of 60 mm. For a standard white plate therein, barium sulfate was used. In order to set the sample to a sample holder attached to the integrating sphere, two thick pieces of paper were prepared which were each prepared by cutting out a rectangular slit of 2.5 cm long×1 cm wide from the center of a rectangle of 6 cm long×3 cm wide. The sample, which is in a sheet form, was cut into a piece of the paper in the form of a rectangle of 6 cm long×3 cm wide, and then sandwiched between the two prepared thick paper pieces. The resultant was set to the sample holder. The sample holder was set at a holding position of the integrating sphere, for transmittance-measurement, on an incident ray side of the sphere to direct a metal-layer-formed surface of the sheet onto a light source side of the spectrophotometer. In this state, the visible light transmittance was measured. A purpose of using the thick paper pieces, from which the rectangular slit has been cut out, is to prevent a decline in the precision of the measured value by the generation of creases in the sample. From the same specimen, three samples were prepared. The average value of measurement data on the three samples was used as the visible light transmittance of the specimen.

<L* Value>

The average value was calculated by measuring 4-ply measured fabric 3 times at the same place under the following conditions.

Color measuring instrument: CM-3700d manufactured by Konica Minolta Inc., measuring diameter: 8 mm, light source: D65, and viewing angle: 2°.

<Visual Inspection Transparency>

Each gray scale for a JIS dyeing fastness test was leaned against the center of a rear wall face of a standard light source device to have an angle of 45° toward the upside. The gray scale surface was covered with a sample to be measured so as to bring the two into contact with each other. From a position 50 cm ahead of the sample to be measured, a peek at the gray scale was made. The perceivability of the sample was evaluated by judging whether or not a border line between the white and gray of the gray scale could be perceived. The visual inspection transparency was determined into a class on the basis of a lowest gray scale class about which the border line can be perceived among the classes of the used gray scales. In the invention, this measurement was made three times by varying the position to be measured. The resultant class numbers were averaged. The average value was used to evaluate the visual inspection transparency.

The used standard light source device is as follows: Verivide CAC 60 (apparatus for standard visual assessment of color by reflectance & transmission) manufactured by Leslie Hubble Limited.

Light source: Artificial Daylight BS950PEL, F20T12/D65, manufactured by Verivide.

<Air Permeability>

The air permeability of the woven fabric is measured with reference to the air permeability A method (Frazier type method) prescribed in JIS L 1096 8. 27. 1.

<Tear Strength>

The tear strength of the woven fabric is measured with reference to the tear strength D method (pendulum method) prescribed in JIS L 1096 8.15.5. The tear strength is measured both in the warp and the weft directions.

<Thickness>

The thickness of the woven fabric is measured with reference to the thickness of the woven fabric prescribed in JIS L 1096 8.5.1.

<Woven Fabric Dyeing Method>

An open soaper was used to refine any woven fabric. A pin tenter was used to set the woven fabric thermally at 190° C. for 30 seconds (pre-setting). A jet dyeing machine (CIRCULAR NS, manufactured by Hisaka Works Ltd.) was used to dye the woven fabric in the usual way with an acid dye when the woven fabric was made mainly of nylon, or with a dispersed dye when the woven fabric was made mainly of polyester. At each dye concentration shown in Table 1, the woven fabric was dyed into beige, gray or dark gray, and then set thermally at 180° C. for 30 seconds (middle setting). Thereafter, the woven fabric was successively subjected to calendering, and water repellent treatment with fluorine resin if necessary.

In the table, the unit of each of the dye concentrations is % owf (on the weight of fiber).

Manner of dyeing the polyester woven fabric with the dispersed dye:

Dye: The kind and the addition amount thereof are described in Table 1

Level dyeing agent: DISPER TL manufactured by Meisei Chemical Works, Ltd.; 1 g/L

pH adjustor: Acetic acid/ammonium acetate are used to adjust the pH to 5

Dyeing conditions: 130° C. for 45 minutes; and bath ratio=1:12

Manner of dyeing the nylon woven fabric with the acid dye:

Dye: The kind and the addition amount thereof are described in Table 1

Level dyeing agent: LEVERON TL manufactured by Ipposha Oil Industries Co., Ltd.; 1 g/L

pH adjustor: Acetic acid/ammonium acetate are used to adjust the pH to 5

Dyeing conditions: 95° C. for 45 minutes; and bath ratio=1:12

TABLE 1 Dark Beige Gray gray Dye concentration Kayanol milling Yellow 5GW 0.14 0.4 1 for nylon6 woven Kayanol milling Red RS125 0.07 0.2 0.5 fabric (% owf) Kayanol Navy Blue R 0.04 0.4 1 Dye concentration Daianix Yellow ACE 0.1 0.4 — for polyester woven Daianix Red ACE 0.06 0.2 — fabric (% owf) Daianix Blue ACE 0.04 0.4 —

Example 1

Using the polymer chips of a relative viscosity of 3.5, wherein the relative viscosity was raised by solid-phase polymerization of nylon 6 having a relative viscosity of 2.2 and containing no titanium oxide (NY6, super bright) polymer chips (manufactured by Toyobo Co., Ltd.), the polymer chips were melted and spun from a spinning mouth having 7 round holes at a spinning temperature of 288° C. Setting three godet rollers in the spinning machine to 2000 m/minute (the first godet roller), 3500 m/minute (the second godet roller), and 3500 m/minute (the third godet roller) in the order from the upstream side and heating the second godet roller to 153° C., the yarn was extended. In this way, a multifilament was yielded which had a fineness of 11 dtex and was composed of 7 monofilaments each having a round cross-section. The breaking strength and the breaking elongation of the resultant multifilament were evaluated by the above-mentioned methods. The results are shown in Table 2.

The multifilament was used as each of warp and weft, and woven into a mini-rip weave (ripstop taffeta weave) illustrated in FIG. 2 under conditions that the warp density and the weft density were set to 254 multifilaments/2.54-cm and 225 multifilaments/2.54-cm, respectively.

In the usual way, an open soaper was used to refine the resultant woven fabric, and then a pin tenter was used to set the woven fabric thermally at 190° C. for 30 seconds. Thereafter, one surface (back surface) of the woven fabric was subjected to calendering (calendering conditions: a temperature of 150° C., a pressure of 2.45 MPa (25 kgf/cm²), and a speed of 20 m/minute) two times. Thereafter, the following were given thereto while the mangle pressure was adjusted to give a wet pickup of 50%: a 1% solution of a fluorine water repellent having a perfluoroalkyl group but substantially containing no perfluorooctanoic acid (PFOA) (“ASAHIGUARD (registered trade mark) Ag-E061”, manufactured by Asahi Glass Co., Ltd.); and a 1% solution of a silicone softener (“NICCA SILICONE (registered trademark) DM-100”, manufactured by Nicca Chemical Co., Ltd.). The woven fabric was then dried and cured at 190° C. for 1 minute to be finished. The resultant woven fabric was a woven fabric in which the density in the warp direction was 275 multifilaments/2.54-cm, the density in the weft direction was 244 multifilaments/2.54-cm, and the cover factor (CF) was 1589. About the resultant woven fabric, the visible light transmittance, the L* value, the visual inspection transparency, the air-permeability, the tear strength, and the thickness were measured by the above-mentioned methods. The results are shown in Table 2.

Example 2

The nylon 6 polymer chips having a relative viscosity of 2.2 were used and spun into a multifilament yarn having a total fineness of 22 dtex and composed of 20 monofilaments. In Example 2, a woven fabric was produced by the same method as in Example 1 except that the weave was changed to plain weave, and the woven fabric was dyed into beige by the above-mentioned method. The resultant woven fabric is evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 3

A woven fabric was produced by the same method as in Example 1 except that the woven fabric described in Example 1 was dyed into gray. The resultant multifilament and woven fabric are evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 4

Using the polymer chips of a intrinsic viscosity 0.75 and containing titanium oxide of 0.01%, wherein the intrinsic viscosity was raised by solid-phase polymerization of polyethylene terephthalate (PET) polymer chips having a intrinsic viscosity 0.62 (manufactured by Toyobo Co., Ltd.), the polymer chips were spun to yield the multifilament having a fineness of 16 dtex and was composed of 24 monofilaments. A woven fabric was produced by the same method as in Example 1 except that this multifilament was used, the gray woven fabric density was changed, and the woven fabric was dyed into beige. The resultant multifilaments and woven fabric are evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 5

A multifilament and a woven fabric were produced by the same method as in Example 1 except that the woven fabric was dyed into beige and subjected to middle setting, and then calendering was applied to the back surface two times, and to the front surface once. The resultant multifilaments and woven fabric are evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 6

A multifilament and a woven fabric were produced by the same method as in Example 1 except that titanium oxide was added (for semi-dullness) in a proportion of 0.2% to the nylon 6 polymer chips used in Example 1, the woven fabric was dyed into beige, and no water repellent treatment (with the fluorine resin) was conducted in the finishing step. The resultant woven fabric is evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 7

A multifilament and a woven fabric were produced by the same method as in Example 1 except that the total fineness of the multifilament was set to 22 dtex, the number of the monofilaments was changed to 20, and the woven fabric was dyed into gray. The resultant woven fabric is evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 8

A multifilament and a woven fabric were produced by the same method as in Example 7 except that the woven fabric was dyed into beige, and in the finishing step neither calendering nor water repellent finishing was conducted. The resultant woven fabric is evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 1

A multifilament and a woven fabric were produced by the same method as in Example 7 except that the woven fabric was dyed into dark gray. The resultant woven fabric is evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 2

The following was used: polyethylene terephthalate (PET) polymer chips (manufactured by Toyobo Co., Ltd.) into which titanium oxide was added in a proportion of 0.01% to show an intrinsic viscosity of 0.62. From the chips, a multifilament having a total fineness of 33 dtex and composed of 24 monofilaments was yielded. A woven fabric was produced by the same method as in Example 1 except that the woven fabric was dyed into gray. The resultant woven fabric is evaluated in the same manner as in Example 1. The results are shown in Table 2.

TABLE 2 Example 1 Example 2 Example 3 Example 4 Example 5 Warp Raw material (resin) NY6 NY6 NY6 PET NY6 Weft Relative viscosity 3.5 2.2 3.5 0.75 3.5 (Intrinsic viscosity*1) Amount of titanium oxide (%) 0 0 0 0.01 0 Refractive index 1.50 1.50 1.50 1.57 1.50 Total fineness (dtex)/ 11T7f 22T20f 11T7f 16T24f 11T7f Number of filaments Single yarn fineness (dtex) 1.6 1.1 1.6 0.7 1.6 Breaking strength (cN/dtex) 5.5 4.0 5.5 5.5 5.5 Breaking elongation (%) 45.0 35.0 45.0 40.0 45.0 Woven Density of the gray fabric 254 × 225 160 × 160 254 × 225 235 × 178 254 × 225 fabric (warp × weft, threads/inch) Weaving pattern Ripstop Plain Ripstop Ripstop Ripstop Cover factor (CF) 1589 1501 1589 1652 1589 Density of the finished fabric 275 × 244 176 × 170 275 × 244 255 × 198 275 × 244 (warp × weft, threads/inch) Weight per unit area (g/m²) 26 31 26 38 26 Finishings Color of the fabric None Beige Gray Beige Beige (White) Calendering Back Back Back Back Back & Front Water repellent treatment Done Done Done Done Done Evaluation Visible light transmittance (%) 66 46 39 48 55 L* value 93 73 45 74 73 Visual inspection transparency 4.5 3.5 3.2 3.5 4 (class number) Air permeability (cc/cm²/s) 0.8 0.8 0.8 0.8 0.6 Tear strength (warp/weft) (N) 15 × 12 8 × 8 15 × 12 11 × 10 10 × 10 Thickness (mm) 0.04 0.05 0.04 0.05 0.04 Comparative Comparative Example 6 Example 7 Example 8 Example 1 Example 2 Warp Raw material (resin) NY6 NY6 NY6 NY6 PET Weft Relative viscosity 3.5 3.5 3.5 3.5 0.62 (Intrinsic viscosity*1) Amount of titanium oxide (%) 0.2 0 0 0 0.01 Refractive index 1.50 1.50 1.50 1.50 1.57 Total fineness (dtex)/ 11T7f 22T20f 22T20f 22T20f 33T24f Number of filaments Single yarn fineness (dtex) 1.6 1.1 1.1 1.1 1.4 Breaking strength (cN/dtex) 5.5 5.5 5.5 5.5 3.3 Breaking elongation (%) 45.0 45.0 45.0 45.0 30.0 Woven Density of the gray fabric 254 × 225 160 × 160 160 × 160 160 × 160 200 × 135 fabric (warp × weft, threads/inch) Weaving pattern Ripstop Ripstop Ripstop Ripstop Ripstop Cover factor (CF) 1589 1501 1501 1501 1501 Density of the finished fabric 275 × 244 174 × 168 170 × 162 174 × 168 220 × 155 (warp × weft, threads/inch) Weight per unit area (g/m²) 26 31 31 31 46 Finishings Color of the fabric Beige Gray Beige Dark gray Gray Calendering Back Back None Back Back Water repellent treatment None Done None Done Done Evaluation Visible light transmittance (%) 55 35 42 14 19 L* value 73 38 73 24 36 Visual inspection transparency 3.7 3.0 3.3 0.0 0.7 (class number) Air permeability (cc/cm²/s) 1.3 0.8 2.0 0.7 0.7 Tear strength (warp/weft) (N) 11 × 11 11 × 11 20 × 20 13 × 11 19 × 18 Thickness (mm) 0.04 0.05 0.06 0.05 0.07

The woven fabrics of Examples 1 to 8 were high in transparency, light, thin, and large in tear strength.

By contrast, the woven fabric of Comparative Example 1 was low in transparency since the woven fabric was dyed into the dark gray. Moreover, in Comparative Example 2, the color of the woven fabric itself was an intermediate color. However, the resultant woven fabric was poor in transparency since the fineness of the multifilament was large.

The present invention is used suitably for a side cloth of a down wear, a down jacket, a futon, a sleeping bag or the like. 

What is claimed is:
 1. A woven fabric, comprising a multifilament having a single yarn fineness of 0.5 to 3.0 dtex and a total fineness of 3 to 25 dtex, wherein the woven fabric has a cover factor of 1300 to 2500, a visible light transmittance of 25% to 80%, and an L* value of 37 or higher.
 2. The woven fabric according to claim 1, wherein the multifilament has a refractive index of 1.47 to 1.57 in a fiber cross-sectional direction.
 3. The woven fabric according to claim 1, wherein the multifilament contains titanium oxide in an amount of 0% to 0.5% by mass, and the multifilament has a breaking strength of 3.5 to 10 cN/dtex.
 4. The woven fabric according to claim 1, wherein at least one surface of the woven fabric is subjected to calendering, and the woven fabric has a fluorine resin coating on a surface thereof.
 5. A down jacket comprising: a woven fabric as set for in claim 1 as a side cloth; and a colored batting. 